Assessing urban vulnerability to flood hazard in Brazilian municipalities

The rise in extreme weather events, coupled with the acknowledgement by policymakers that vulnerable populations are disproportionately at risk, has led to an increase in demand for vulnerability assessments, and particularly composite vulnerability indices. This paper presents a flood hazard vulnerability index that incorporates socioeconomic, built environment and natural environment data, and that was used to measure the vulnerability of 1,276 municipalities in Brazil. Findings show that 83 of these municipalities (with 22 per cent of the Brazilian population) are at risk. Vulnerability stemming from lower levels of socioeconomic status is concentrated in the Northern regions; that related to poor governance is widespread across all regions. This analysis highlights the dangers of assessing vulnerability using aggregate measures of socioeconomic status in middle-income countries with high levels of inequality, where the presence of vulnerable populations in informal settlements within highly developed municipalities may be obscured.